1. Technical Field
The invention relates to a wellbore treatment process and more particularly to a wellbore treatment process wherein the wellbore penetrates a subterranean hydrocarbon-bearing formation.
2. Description of Related Art
Portland cement is commonly used in oil field applications such as oil well cement jobs. Portland cements can be tailor-made for the specific conditions of each well. A description of the state of the art in oil well cementing technology is given in Basic Cementing, Petroleum Publishing Co., 1977 (reprinted from a series of articles appearing in the Oil and Gas Journal) and Rike, J. L., et al, Squeeze Cementing: State of The Art, Journal of Petroleum Technology, (January 1982), pp. 37-45.
Formulation of the cement in the field is largely a product of trial and error by field personnel to meet irregularities in the cementing composition and the downhole environment. Cement quality control is difficult to achieve under such conditions. As a result, Portland cement can exhibit premature set-up, cracking, or shrinking upon curing. This feature of Portland cement limits its usefulness in wellbore treatments to repair leaks in wellbore casing or tubing by plugging the tubing/casing pair annulus. Use of other available methods to remedy leaking wellbore tubulars, including workovers and redrilling, can be extremely cumbersome and expensive.
A wellbore treatment process is needed for preventing or repairing leaking tubulars which is both economically and operationally attractive. A process is needed which effectively employs a plugging material having a broad range of highly controllable and predictable set-up times for ease of operation and design. A process is needed which employs a plugging material which is not as susceptible as Portland cement to shrinking and cracking when applied to a tubing/casing annulus in a wellbore.